CONTROL METHOD AND CONTROL DEVICE FOR AIR CONDITIONING SYSTEM, AND AIR CONDITIONING SYSTEM

Description

PRIORITY STATEMENT

This application claims benefit of Chinese Patent Application No. 202411125854.2, filed Aug. 15, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in their entirety are herein incorporated by reference.

BACKGROUND

This application relates to the air conditioning field, and specifically to a control method for an air conditioning system, a control device for executing the control method, and an air conditioning system using the control method or including the control device.

SUMMARY

An object of this application is to provide a control method and control device for an air conditioning system, and an air conditioning system using the control method or including the control device, so that some problems in the related art can be resolved or alleviated.

This application provides a control method for an air conditioning system. The air conditioning system to which the control method is applicable includes a compressor, a main heat valve, a condenser, a liquid reservoir, an expansion valve, and an evaporator which are connected in sequence to form a refrigerant circulation loop; a hot gas valve having one end connected to an outlet of the compressor and the other end connected to an inlet of the evaporator; and a liquid injection valve having one end connected to an outlet of the evaporator and the other end connected to the liquid reservoir. The control method according to this application includes: an air conditioning system setting mode determination step of determining whether the air conditioning system is set to a specified mode; a hot gas valve opening step of opening the hot gas valve; a main heat valve closing step of closing the main heat valve according to a determination result of the air conditioning system setting mode determination step; a liquid injection valve opening step of opening the liquid injection valve; a compressor starting step of starting the compressor to operate in the specified mode; and a liquid injection valve closing step of closing the liquid injection valve when a specified closing condition is satisfied.

In one or more embodiments, the specified mode is a heating mode.

In one or more embodiments, the specified closing condition is that a specified time N passes after the compressor starting step is executed.

In one or more embodiments, the specified closing condition is that a specified heating temperature is reached after the compressor starting step is executed.

In one or more embodiments, the control method further includes a standby operation step of stopping the operation of the compressor, keeping the main heat valve and the liquid injection valve closed, and keeping the hot gas valve opened if a heating temperature set in the heating mode is reached.

In one or more embodiments, the control method further includes a compressor restarting step of restarting the compressor to exit a standby operation mode if a temperature is lower than the heating temperature set in the heating mode.

In one or more embodiments, the air conditioning system further includes a compressor suction pressure regulating valve disposed between an inlet of the compressor and the outlet of the evaporator.

One or more embodiments of this application further provide a control device for an air conditioning system, the control device including: an air conditioning system setting mode determination module configured to determine whether the air conditioning system is set to a specified mode; a hot gas valve opening instruction generation module configured to generate and issue an instruction to open a hot gas valve; a main heat valve closing instruction generation module configured to issue an instruction to close a main heat valve according to a determination result of the air conditioning system setting mode determination module; a liquid injection valve opening instruction generation module configured to generate and issue an instruction to open a liquid injection valve; a compressor starting module configured to start a compressor to operate in the specified mode; and a liquid injection valve closing instruction generation module configured to generate and issue an instruction to close the liquid injection valve when a specified closing condition is satisfied.

One or more embodiments of this application further provide an air conditioning system including a memory and a control device, in which the control device executes any one of the above control methods for an air conditioning system.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic diagram of an air conditioning system including an FCV device in one or more embodiments of this application.

FIG. 2 is a schematic diagram of steps executed in a control method for an air conditioning system in one or more embodiments of this application.

FIG. 3 is a schematic diagram of steps executed in a control method for an air conditioning system in one or more embodiments of this application.

FIG. 4 is a schematic diagram of an air conditioning system including an FCV device in one or more embodiments of this application.

FIG. 5 is a schematic diagram of modules in a control device for an air conditioning system in one or more embodiments of this application.

Reference numerals: compressor 1, main heat valve 2, condenser 3, liquid reservoir 4, expansion valve 5, evaporator 6, hot gas valve 7, liquid injection valve 8, compressor suction pressure regulating valve 9, air conditioning system setting mode determination module 101, hot gas valve opening instruction generation module 102, main heat valve closing instruction generation module 103, liquid injection valve opening instruction generation module 104, compressor starting module 105, liquid injection valve closing instruction generation module 106.

DETAILED DESCRIPTION OF THE DISCLOSURE

It should be noted that working principles, features, advantages, and the like of a refrigeration apparatus according to this application will be explained below by way of embodiments. However, it should be understood that all descriptions are only given for exemplification and therefore these embodiments should not be understood as forming any limitation on this application.

In addition, for any single technical feature described or implicit in the embodiments mentioned herein, or any single technical feature illustrated or implicit in the drawings, this application still allows any combination or deletion between these technical features (or equivalents thereof) without any technical obstacles, thereby obtaining more other embodiments of this application that may not be directly mentioned herein.

In an air conditioning system of existing configurations, when a load changes or an operation mode of the air conditioning system changes, a flow rate of a refrigerant can be regulated by a flow control valve (FCV) device, that is, the flow rate of the refrigerant is regulated according to a current actual load demand of the air conditioning system. If the load is low, the flow rate of the refrigerant in a refrigerant circulation is reduced by regulating the FCV device to avoid excessive cooling, thereby adapting to the load and saving energy. If the load is high, the flow rate of the refrigerant in the refrigerant circulation is increased by regulating the FCV device to satisfy higher cooling or heating requirements.

In general, an indoor heat load in winter is less than an indoor cooling load in summer. When the air conditioning system is switched to a heating mode, a required amount of the refrigerant is less than that in a cooling mode. The flow rate of the refrigerant in a refrigerant circulation pipeline can be reduced by regulating switching of a valve in the FCV device to control the refrigerant to flow into a liquid reservoir, thereby adapting to the load and saving energy.

However, if the flow rate of the refrigerant in the refrigerant circulation pipeline is insufficient because the control of the FCV device causes too much refrigerant to flow into the liquid reservoir, there is a problem that the air conditioning system cannot provide the required load.

The control method for an air conditioning system, a control device for executing the control method, and an air conditioning system using the control method or including the control device

FIG. 1 is a schematic diagram of an air conditioning system including a flow control valve (FCV) device in one or more embodiments of this application. As shown in FIG. 1, the air conditioning system including the FCV device includes: a compressor 1, a main heat valve 2, a condenser 3, a liquid reservoir 4, an expansion valve 5, an evaporator 6, a hot gas valve 7, and a liquid injection valve 8. The flow control valve (FCV) device mainly includes the main heat valve 2, the expansion valve 5, the hot gas valve 7, and the liquid injection valve 8.

As shown in FIG. 1, the compressor 1, the main heat valve 2, the condenser 3, the liquid reservoir 4, the expansion valve 5, and the evaporator 6 are connected in sequence by a refrigerant pipeline to form a refrigerant circulation loop. One end of the hot gas valve 7 is connected to an outlet of the compressor 1, and the other end thereof is connected to an inlet of the evaporator 6. One end of the liquid injection valve 8 is connected to an outlet of the evaporator 6, and the other end thereof is connected to the liquid reservoir 4.

FIG. 2 is a schematic diagram of steps executed in a control method for the air conditioning system shown in FIG. 1. Referring to FIG. 2, the control method for the air conditioning system according to some embodiments includes: an air conditioning system setting mode determination step S1, a hot gas valve opening step S2, a main heat valve closing step S3, a liquid injection valve opening step S4, a compressor starting step S5, and a liquid injection valve closing step S6.

In one or more embodiments of this application, when the air conditioning system receives an instruction to start operation, the air conditioning system setting mode determination step S1 is executed to determine whether the air conditioning system is set to a specified mode, and if the air conditioning system is set to the specified mode, the hot gas valve opening step S2 is executed to open the hot gas valve 7, and the main heat valve closing step S3 and the liquid injection valve opening step S4 are executed at the same time to close the main heat valve 2 and open the liquid injection valve 8. After the opening and closing of valves performed by the hot gas valve opening step S2, the main heat valve closing step S3, and the liquid injection valve opening step S4 are completed, the compressor starting step S5 is executed to control the compressor 1 to start the operation in the specified mode. In this case, the main heat valve 2 is in a closed state, and the hot gas valve 7 is in an open state. After the compressor 1 starts the operation in the specified mode, a refrigerant flows out of the outlet of the compressor 1, passes through the hot gas valve 7, flows into the evaporator 6, and exchanges heat with the air in the evaporator 6. After the heat exchange is completed, a part of the refrigerant flowing out of the evaporator 6 flows into the compressor 1, and the other part of the refrigerant flows into the liquid reservoir 4 through the liquid injection valve 8 and is stored in the liquid reservoir 4. When the air conditioning system satisfies a specified closing condition, the liquid injection valve closing step S6 is executed to close the liquid injection valve 8.

Specifically, when the air conditioning system is set to the specified mode, the main heat valve 2 is in the closed state, and thus the refrigerant flowing out of the outlet of the compressor 1 cannot flow into the condenser 3, but flows directly into the evaporator 6 through the hot gas valve 7 having one end connected to the outlet of the compressor 1 and the other end connected to the inlet of the evaporator 6 to form a triangle circulation, and the evaporator 6 is used as a heat exchanger for heat exchange with the outside, and the refrigerant is no longer condensed by the condenser. When the air conditioning system operates in this mode, the compressor 1 works to increase a temperature of the refrigerant, and the refrigerant whose temperature is increased flows to the evaporator 6 through the hot gas valve 7, and exchanges heat with the outside air in the evaporator 6 to increase a temperature of the outside air. The air whose temperature is increased can be used to provide heat for a van or any other indoor space that needs to adjust a temperature. A part of the cooled refrigerant flowing out of the evaporator 6 flows into and is stored in the liquid reservoir 4 through the liquid injection valve 8, and the other part of the cooled refrigerant is transported to the compressor 1 through the refrigerant circulation loop, and is heated and pressurized by the compressor 1 to continue heating circulation. Further, when the air conditioning system operates until the specified closing condition is satisfied, the liquid injection valve closing step S6 is executed to close the liquid injection valve 8, so that the refrigerant at the outlet of the evaporator 6 no longer flows into the liquid reservoir 4 through the liquid injection valve 8.

According to the above manner, when the air conditioning system is switched to a heating mode and an indoor heat load is small, by controlling the hot gas valve 7 and the liquid injection valve 8 to be opened and controlling the main heat valve 2 to be closed, and then starting the compressor 1, the air conditioning system starts the operation in the heating mode, and at the same time, a part of the refrigerant flows through the hot gas valve 7 and the liquid injection valve 8, and flows into and is stored in the liquid reservoir 4, so that a flow rate of the refrigerant in a refrigerant circulation pipeline is reduced, thereby adapting to a lower indoor heat load and saving energy. When the air conditioning system operates until the specified closing condition is satisfied (for example, when a set indoor temperature is reached or any other specified closing conditions determined in advance are satisfied), the liquid injection valve 8 is controlled to be closed. In this case, the refrigerant flowing out of the evaporator 6 no longer flows to the liquid reservoir 4 through the liquid injection valve 8, but enters the compressor 1 for a triangle heating circulation, so as to avoid a problem that the refrigerant involved in heating continues to decrease when the liquid injection valve 8 is kept open, resulting in a decrease in a heating capacity.

In some embodiments of this application, in the liquid injection valve closing step S6, the specified closing condition is that a specified time N passes after the compressor starting step S5 is executed.

Specifically, when the air conditioning system is switched to the heating mode, the hot gas valve 7 is opened, the main heat valve 2 is closed, and the liquid injection valve 8 is opened. After the specified time N, such as 10 minutes, passes after the compressor starting step S5 is executed, the liquid injection valve closing step S6 is executed to control the liquid injection valve 8 to be closed.

According to the above manner, within the specified time N after the compressor starting step S5 is executed, a part of the refrigerant flows into and is stored in the liquid reservoir 4 through the liquid injection valve 8. After the air conditioning system operates for the specified time N, the liquid injection valve closing step S6 is executed, that is, the liquid injection valve 8 is closed, and the refrigerant flowing out of the evaporator 6 is controlled not to flow into the liquid reservoir 4 through the liquid injection valve 8, and enough refrigerant in the heating triangle circulation including the compressor 1, the evaporator 6, and the hot gas valve 7 is ensured for the heating circulation, thereby avoiding a problem that when the air conditioning system is operating in the heating mode, the refrigerant involved in the heating circulation continues to decrease, resulting in a decrease in the heating capacity of the air conditioning system, and affecting an indoor thermal environment.

In some embodiments of this application, in the liquid injection valve closing step S6, the specified closing condition is that a specified heating temperature is reached after the compressor starting step S5 is executed.

When the air conditioning system is switched to the heating mode, the hot gas valve 7 is opened, the main heat valve 2 is closed, and the liquid injection valve 8 is opened. After the compressor starting step S5 is executed, if an indoor ambient temperature reaches a set temperature of the air conditioning system, the liquid injection valve closing step S6 is executed to control the liquid injection valve 8 to be closed.

Specifically, for example, the specified closing condition set in advance is that after 10 minutes after the compressor starting step S5 is executed, the liquid injection valve closing step S6 is executed. However, even if the indoor ambient temperature reaches the set temperature of the air conditioning system after 15 minutes after the compressor 1 is started in the actual operation of the air conditioning system, the liquid injection valve closing step S6 is still executed after the specified time N (for example, 10 minutes) after the compressor starting step S5 is executed, and the liquid injection valve 8 is controlled to be closed. That is, if the specified time N passes after the compressor starting step S5 is executed, regardless of whether the indoor ambient temperature reaches the set temperature of the air conditioning system, the liquid injection valve 8 is controlled to be closed to avoid excessive decrease of the refrigerant involved in the heating circulation and the decrease in the heating capacity of the air conditioning system. The set temperature of the air conditioning system can be reached by continuing heating for a period of time in the subsequent heating triangle circulation including the compressor 1, the evaporator 6, and the hot gas valve 7.

On the other hand, if it is detected that the indoor ambient temperature reaches the set temperature of the air conditioning system after a time, such as 5 minutes that is less than 10 minutes, which is the specified time N, passes after the compressor starting step S5 is executed during the actual operation of the air conditioning system, the liquid injection valve closing step S6 is directly executed after 5 minutes after the compressor starting step S5 is executed, and the liquid injection valve 8 is controlled to be closed. That is, if the specified time N has not yet passed when the indoor ambient temperature is reached, the liquid injection valve 8 is also controlled to be closed. In this case, since the indoor ambient temperature has reached the set temperature, it is necessary to control the continuous reduction of the refrigerant in time to ensure an appropriate heating capacity of the air conditioning system in the later stage.

According to the above manner, after the air conditioning system executes the compressor starting step S5, an opening time of the liquid injection valve 8 is controlled by comprehensively referring to two factors, that is, the indoor ambient temperature and whether the air conditioning system operates in the heating mode for the specified time N, so that the flow rate of the refrigerant, which is involved in the heating circulation, in the refrigerant circulation pipeline can be accurately controlled, thereby saving energy while ensuring the heating capacity of the air conditioning system, that is, according to different indoor and outdoor environmental parameters, operating parameters of the air conditioning system comprehensively control the flow rate of the refrigerant involved in the heating circulation, and the indoor thermal environment and the operating capacity of the air conditioning system are ensured.

Although an example in which the specified time N is set to 10 minutes is described in some embodiments, this application is not limited thereto, and according to outdoor environmental parameters and indoor temperature in different regions, and model parameters of the air conditioning system, the setting of the specified time N can be flexibly regulated by preliminary experiments or calculations, which is also included in the protection scope of this application.

In addition, in some embodiments, the specified closing condition of the liquid injection valve 8 is that the specified time N passes or the specified heating temperature is reached after the compressor starting step S5 is executed, but this application is not limited thereto, and according to different models and operation modes of the air conditioning system, different specified closing conditions of the liquid injection valve 8 can be set, which is also included in the protection scope of this application.

FIG. 3 is a schematic diagram of steps executed in the control method for an air conditioning system in the embodiment of this application. Referring to FIG. 3, in some embodiments the control method for an air conditioning system further includes: a standby operation step S7 of stopping the operation of the compressor 1, keeping the main heat valve 2 and the liquid injection valve 8 closed, and keeping the hot gas valve 7 opened if the heating temperature set in the heating mode is reached.

After the air conditioning system operates in the heating mode for a period of time, if it is detected that the indoor ambient temperature reaches the heating temperature set in the heating mode, the standby operation step S7 is executed to control the air conditioning system to enter a standby operation mode. Specifically, in this case, the compressor 1 stops operating, the main heat valve 2 and the liquid injection valve 8 remain closed, and the hot gas valve 7 remains open. Specifically, if the indoor ambient temperature does not reach the heating temperature set in the heating mode within the specified time N after the air conditioning system is switched to the heating mode, when the air conditioning system operates for the specified time N, the liquid injection valve closing step S6 is executed to control the liquid injection valve 8 to be closed. In this case, the compressor 1 continues operating, and the refrigerant flowing out of the evaporator 6 no longer flows into the liquid reservoir 4 through the liquid injection valve 8, but all flows into the compressor 1 to continue performing the heating circulation. If the indoor ambient temperature reaches the heating temperature set in the heating mode, the standby operation step S7 is executed, that is, the compressor 1 is controlled to stop operating, the main heat valve 2 and the liquid injection valve 8 remain closed, and the hot gas valve 7 remains open.

If the indoor ambient temperature reaches the heating temperature set in the heating mode before the specified time N after the air conditioning system is switched to the heating mode, instead of continuing operating for the specified time N, the liquid injection valve closing step S6 and the standby operation step S7 are directly executed, the liquid injection valve 8 is switched to the closed state, the air conditioning system is controlled to enter the standby operation mode, and the compressor 1 stops operating.

According to some embodiments, if the indoor ambient temperature reaches the heating temperature set in the heating mode after the air conditioning system operates for a period of time, the air conditioning system is controlled to enter the standby mode, and in this case, the liquid injection valve 8 and the main heat valve 2 are closed, and the hot gas valve 7 is opened. After the air conditioning system is switched to the heating mode, the refrigerant flowing into the liquid reservoir 4 is still stored in the liquid reservoir 4, avoiding a problem in the related art that when the air conditioning system enters the standby mode, the hot gas valve 7 is closed, and the main heat valve 2 is opened, and as a result, the refrigerant is transferred to the condenser, and when the compressor 1 needs to be started again for heating later, an amount of the refrigerant in the refrigerant circulation pipeline is insufficient, and as a result, the heating capacity of the air conditioning system is decreased.

In some embodiments of this application, when the air conditioning system enters the standby mode and detects that the indoor temperature is lower than the heating temperature set in the heating mode, the compressor restarting step S8 is executed to control the compressor 1 to restart and exit the standby operation mode. In this case, the main heat valve 2 and the liquid injection valve 8 are still in the closed state, and the hot gas valve 7 is still in the open state.

In some embodiments, when the air conditioning system exits the standby mode and enters the heating mode again, the flow rate of the refrigerant involved in the heating circulation is still the flow rate of the refrigerant involved in the heating circulation after switching from other modes other than the standby mode to the heating mode for the first time, energy is saved, and at the same time, enough refrigerant involved in the refrigeration circulation is ensured, and a possibility of reduction in the heating capacity of the air conditioning system due to too little refrigerant involved in the heating circulation is reduced. A problem is also avoided that the flow rate of the refrigerant involved in the heating circulation is regulated every time entering or exiting the standby operation mode, and as a result, an operating efficiency of the air conditioning system is reduced.

FIG. 4 is a schematic diagram of an air conditioning system including an FCV device in the embodiment of this application. Referring to FIG. 4, in some embodiments the air conditioning system using the control method for an air conditioning system further includes a compressor suction pressure regulating valve 9 disposed between an inlet of the compressor 1 and the outlet of the evaporator 6.

When the air conditioning system is switched to the heating mode, an opening degree of the compressor suction pressure regulating valve 9 can be regulated to change the flow rate of the refrigerant flowing into the compressor 1. By reducing the flow rate of the refrigerant flowing into the compressor 1 and changing a pressure at the inlet of the compressor 1 and a pressure at the compressor suction pressure regulating valve 9, a part of the refrigerant flowing out of the evaporator 6 can be regulated by the opening degree of the compressor suction pressure regulating valve 9 and flow into the liquid reservoir 4 through the liquid injection valve 8, so that the flow rate of the refrigerant involved in the heating circulation in the heating mode can be flexibly regulated according to working conditions of the compressor 1.

According to the above manner, by adding the compressor suction pressure regulating valve 9 disposed between the inlet of the compressor 1 and the outlet of the evaporator 6, the flow rate of the refrigerant flowing out of the evaporator 6 into the compressor 1 can be more flexibly regulated according to indoor and outdoor environmental parameters, thereby controlling the flow rate of the refrigerant flowing into the liquid reservoir 4 through the liquid injection valve 8. That is, the flow rate of the refrigerant can be regulated by opening degrees of the two valves, that is, the compressor suction pressure regulating valve 9 and the liquid injection valve 8, so that after the air conditioning system is switched to the heating mode, it is ensured that the air conditioning system can reach the set temperature as soon as possible, and the heating capacity of the air conditioning system can be properly controlled.

FIG. 5 is a schematic diagram of modules in the control device for an air conditioning system in the embodiment of this application. As shown in FIG. 5, the control device for an air conditioning system according to some embodiments includes: an air conditioning system setting mode determination module 101, a hot gas valve opening instruction generation module 102, a main heat valve closing instruction generation module 103, a liquid injection valve opening instruction generation module 104, a compressor starting module 105, and a liquid injection valve closing instruction generation module 106.

In some embodiments, when the air conditioning system starts the operation, the air conditioning system setting mode determination module 101 executes the air conditioning system setting mode determination step S1 to determine whether the air conditioning system is set to the specified mode. If the air conditioning system is set to the specified mode, the hot gas valve opening instruction generation module 102 executes the hot gas valve opening step S2 to generate and output a hot gas valve opening instruction to open the hot gas valve 7, and at the same time, the main heat valve closing instruction generation module 103 executes the main heat valve closing step S3 to generate and output a main heat valve closing instruction, and the liquid injection valve opening instruction generation module 104 executes the liquid injection valve opening step S4 to generate and output a liquid injection valve opening instruction, thereby closing the main heat valve 2 and the liquid injection valve 8 respectively. After completing the opening and closing of the hot gas valve 7, the main heat valve 2, and the liquid injection valve 8, the compressor starting module 105 executes the compressor starting step S5 to control the compressor 1 to start the operation in the specified mode. In this case, the main heat valve 2 is in the closed state, and the hot gas valve 7 is in the open state.

After the compressor 1 starts the operation in the specified mode, the refrigerant flows out of the compressor 1, passes through the hot gas valve 7, flows into the evaporator 6, and exchanges heat with the air in the evaporator 6. After the heat exchange is completed, a part of the refrigerant flowing out of the evaporator 6 flows into the compressor 1, and the other part of the refrigerant flows into the liquid reservoir 4 through the liquid injection valve 8 and is stored in the liquid reservoir 4. When the air conditioning system satisfies the specified closing condition, the liquid injection valve closing instruction generation module 106 executes the liquid injection valve closing step S6, and generates and outputs a liquid injection valve closing instruction to close the liquid injection valve 8.

Specifically, in some embodiments, the air conditioning system setting mode determination module 101 controls and executes the air conditioning system setting mode determination step S1. Similarly, the hot gas valve opening instruction generation module 102 controls and executes the hot gas valve opening step S2, the main heat valve closing instruction generation module 103 controls and executes the main heat valve closing step S3, the liquid injection valve opening instruction generation module 104 controls and executes the liquid injection valve opening step S4, the compressor starting module 105 controls and executes the compressor starting step S5, and the liquid injection valve closing instruction generation module 106 controls and executes the liquid injection valve closing step S6.

One or more embodiments of this application further provides an air conditioning system including a memory and a control device, in which the control device executes any one of the above control methods for an air conditioning system.

The above embodiments are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included in the protection scope of this application.